Prop Questions

What kind of prop are running and what kind of speeds/RPMs do get out of it?

Wailana = Old Martec 2 bladed ungeared folder = 5.5 kts under power with no wind at 2800 RPM but we cruise at 5 kts. at 2600 RPM. Now that’s with a clean bottom with no dinghy.
Anything over 2600 and we get a loud and shaky vibration.

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3 thoughts on “Prop Questions

  1. MARK WILLIAMS

    I think when I reproped lots of years ago we ended up with 14″ x12 prop. I would give Martec a call and give them the parameters of the boat and most likely they can replace the blades on your hub and it is a lot cheaper then a new prop. We have had ours rebladed once due to galvanic corrosion as the harbor we moor in is a “hot” harbor as far as stray electrical current. Obviously check the cutlass bearing when the boat is out of the water for any play. We motor at 3000-3100 without issues and that Yanmar is designed to run at high rpm’s without any problems. at those rpms we motor at 6.4 towing a 10ft rib dingy. I have always felt the E34 motored better then it should and when we raced heavily many competitors commented on our motoring speed for a 34 ft boat. As far as light air performance and performance in general make sure you have enough mast rake as this boat needs it.

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  2. Jim

    Hello Mark,
    I finally got around to investigating the motoring speed of Houdini and once I took a DA to the roots on the Martec prop I found it had a 16X8 on there. We would get 5.5kts in flat water at 3K RPM. I did a bunch of reading and decided to go with a Flexofold as we cruise the boat a lot and the Flexofold seems to be knows for their speed. I talked to the US distributor and he recommended a 15X11 and ordered one up and it was received from DK in 4 days. Houdini splashed a week ago and I can say the difference was worth every penny. We are now doing 6.7-6.9kts at 2600-2700RPM and she does 7.2 at 3K RPM, at WOT throttle she will pull 3300-3400RPM and 7.5kts but is pretty darn smokey. I am thinking that we will now run the motor at 26-2700 for normal cruising and 3K if we are in a rush. If I had to do it over again I think a 15X10 or 16X10 would be the sweet spot as she will not make red-line any longer with the deeper pitched prop.

    It was an expensive upgrade but with a planned cruise out to the Vinyard and surrounding areas later this summer it will be much appreciated if we have the weather we had last year during our cruise.

    Cheers,
    Jim

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  3. Pingback: Flexofold prop installed! | Alsberg Express 34

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